(a) Field of the Invention
The present invention relates to a handheld clamping tool and more particularly, to a simple design of handheld clamping tool, which is adjustable between two modes for clamping application or expansion application.
(b) Description of the Prior Art
Conventional handheld clamping tools are generally designed for clamping or expanding an object. A handheld clamping tool is known comprising a bracket, a sliding bar, a handle holder, a driving handle, a first jaw and a second jaw. The first jaw is mounted at the top side of the bracket. The second jaw is mounted at the top side of the handle holder. When continuously pressing the driving handle, the first and second jaws will be moved relative to each other for clamping or expansion application. Taiwan Patent M344953 (equivalent to China Patent 200810006515.5 or U.S. Pat. No. 7,513,492) discloses a similar design, entitled “Hand held quick-clamping device”.
According to conventional designs, the mounting position between the bracket and the sliding bar can be adjusted to have the first jaw and the second jaw be disposed facing each other for clamping application, or in reversed directions for expansion application. When the two jaws are arranged facing each other, the handheld clamping tool can be used to clamp an object. On the contrary, when the two jaws are arranged in reversed directions, the handheld clamping tool can be used to expand an object. Thus, the mounting position between the bracket and the sliding bar must be properly changed to fit different application requirements, i.e., the bracket can be located at one end of the sliding bar for clamping application, or at the other end of the sliding bar for expansion application. Thus, the user may have to frequently detach the bracket from one end of the sliding bar and then attach the bracket to the other end of the sliding bar.
According to conventional designs, a lock screw is inserted through the bracket and a lock hole at one end of the sliding bar and then screwed up with a nut to lock the bracket to the sliding bar. When going to change the operation mode of the handheld clamping tool, the user must remove the nub and the lock screw from the bracket and the sliding bar, and then insert the lock screw through the bracket and a second lock hole at the other end of the sliding bar and then thread the nut onto the lock screw to lock the bracket and the sliding bar. This operation procedure is complicated, requiring much labor and time.
U.S. Pat. No. 6,945,523 discloses a clamping tool comprising a displaceable and repositionable fixed clamping jaw. According to this design, a push button is provided for operation control, and a U-shaped catch member having a shorter U-leg and a longer U-leg is used to carry the push button. This structural design is complicated. Installation of the component parts is inconvenient and complicated.